AD FAA-2024-0458

The FAA is adopting a new airworthiness directive (AD) for all ATR-GIE Avions de Transport R[eacute]gional Model ATR42 and ATR72 airplanes. This AD was prompted by a report of incorrect marking and assembly of the two-way valves for the left- and right-hand engine fire extinguishing systems. This AD requires accomplishing a functional check of an affected part; replacing an affected part if necessary; reporting the functional check results; and prohibiting the installation of affected parts; as specified in a European Union Aviation Safety Agency (EASA) AD, which is incorporated by reference. The FAA is issuing this AD to address the unsafe condition on these products.